1. Field of the Invention
The present invention relates to a DC/DC converter, a light emitting display using the DC/DC converter, and a driving method thereof, and more particularly, to a DC/DC converter, a light emitting display using the DC/DC converter, and a driving method thereof, in which an image is displayed with uniform brightness.
2. Description of the Related Art
Recently, various flat panel displays have been developed, which substitute for a Cathode Ray Tube (CRT) display because the CRT display is relatively heavy and bulky. Flat panel displays include Liquid Crystal Displays (LCDs), Field Emission Displays (FEDs), Plasma Display Panels (PDPs), light emitting displays, etc.
Among the flat panel displays, the light emitting display can emit light of its own by electron-hole recombination. Such a light emitting display has advantages in that its response time is relatively fast and its voltage consumption is relatively low.
A light emitting display comprises: a pixel portion including a plurality of pixels formed adjacent to a region where a plurality of scan lines intersects a plurality of data lines; a scan driver to drive scan lines; a data driver to drive data lines; and a DC/DC converter to supply first voltage and second voltage to the pixels.
The scan driver generates scan signals and supplies the generated scan signals to the scan lines to select the pixels in units of horizontal lines in sequence.
The data driver supplies data signals to the data lines when the scan signals are supplied. As a result, as the data signals are supplied to the selected pixels by the scan signals, light corresponding to the data signal is generated by the pixels.
The DC/DC converter uses an external voltage to generate the first voltage and the second voltage, and supplies the first voltage and the second voltage to each pixel.
Such a light emitting display has a problem in that light of different brightness is emitted from each different frame and/or the location of the scan lines to which the pixels connect even when the equivalent data is supplied due to the ripple present in the first voltage.
If the value of current flowing to each light emitting device of such a light emitting display is set differently for each frame when a data signal having an equivalent gradation value is applied, the problem of degraded image quality occurs due to the difference in brightness for each frame.